The elderly couple wasn’t going to let age keep them from the most exciting adventure of their lives. They put on sturdy walking shoes, donned helmets and harnesses, and zipped for the first time with Skyline Eco-Adventures Akaka Falls on Hawaii island.

"The man was 86 years old, and his wife wasn’t much younger," said Operations Manager Bonnie Blair. "Afterward the woman said, ‘We did just fine,’ and her husband replied, ‘Well, why wouldn’t we?’"

Another customer had a surprise for his sweetheart at the end of their tour. She was last to cross the line, and when she reached the landing, he was waiting on one knee.

"Her two children were also there, holding a banner with ‘Will you marry me?’ written on it," Blair said. "She was very happy and she immediately said yes!"

The Akaka Falls operation is a franchise of Maui-based Skyline Eco-Adventures, which, in 2002, offered the first commercial zip line tour in the United States. The company was founded by Buck Boren and his son Danny, who had zipped in rain forests during their Costa Rican vacation the year prior. They saw the potential for an exhilarating new activity in Hawaii that would immerse visitors in a beautiful setting with minimal impact on the environment.

Kevin Connolly, a 27-year-old professional photographer and award-winning skier who was born without legs, was another memorable guest. "He zipped our last two lines using his own harness, which was connected to our harness with carabiners and tethers," Blair said. "A crew filmed his crossings for the pilot of a TV show called ‘The Kevin Michael Connolly Project’ that the Travel Channel had ordered."

Blair also recalled a terminally ill woman in her 50s who had put zipping in Hawaii on her bucket list. "She did the whole tour with her family and close friends," Blair said. "It was so inspiring to see her living life to the fullest for as long as she could. When she crossed the last line, everyone in the group was teary-eyed, even the guides."

On the Akaka Falls tour, participants cross seven lines in about 21⁄2 hours, although the name is a bit of a misnomer because although famed Akaka Falls is just two miles away, it is not seen on the tour. The lines get progressively longer, from 100 to 3,350 feet. They also range in speed (participants zip 10 to 50 mph, making the crossings in three to 90 seconds). Their height above the ground also varies (5 to 500 feet).

Each line is named after an aspect of nature: Ua (rain), Maia (banana), Wai (fresh water), Kalo (taro), Ko (sugar cane), Puaa (pig) and Wailele (waterfall), which is the longest line in Hawaii.

How the lines got their names is evident as guests navigate the course. Line 2 goes through a banana patch. A 20-foot waterfall is the highlight of Line 3. Wild pigs are often spotted around Line 6. And Line 7 provides a once-in-a-lifetime thrill by carrying participants right over 250-foot Kolekole Falls.

"No words can completely describe what you’re feeling when you’re gliding 200 feet above that spectacular waterfall," Blair said. "It’s a view you could only otherwise see if you had wings. It’s different from looking at it from a helicopter because when you’re zipping, you’re so close to it and you’re right in nature; you’re not enclosed by anything. It’s such a rush! You feel alert and energized; if you zip that line, you don’t need a morning cup of coffee to get you going."

Participants also enjoy views of the ocean, deep ravines, soaring io (endangered Hawaiian hawks) and fields of taro, ginger, sweet potato and wild cane (Mauna Kea Agribusiness, the last sugar enterprise in the area, harvested its final crop in 1994). Guides offer snacks of raw cane and seasonal fruits, which might include banana, guava, lychee, starfruit, strawberry guava, calamansi lime and lilikoi (passion fruit).

Blair quoted a saying that helps define the experience: "Life is not measured by the number of breaths you take, but by the moments that take your breath away."

Cheryl Chee Tsutsumi is a Honolulu-based freelance writer whose travel features for the Star-Advertiser have won several Society of American Travel Writers awards.